Reduced Work Week and Compressed Work Week are a (relatively) new concept that some Annualised Hours Contract workplaces are doing

Reduced: You work 4 days of 7.5 hours, adding up to 30 hours weekly, you get paid the same as if you worked 5 days of 7.5 hours (37.5 hours)

Compressed: You work 4 days of 9.5 hours, adding up to 37.5 hours weekly, you get paid the same as if you worked 5 days of 7.5 hours (37.5 hours)